mcp-kafka proxy

The mcp-kafka proxy binding routes the same fixed set of intrinsic Kafka tools as the client kind, matching by tool name and, for produce_message and consume_messages, by topic, then dispatching each matched tools/call to the route's own exit, or the binding's top-level exit when the route has none — typically a mcp-kafka client connected to a specific Kafka cluster. Unlike client, a proxy binding has no options or vault of its own; it only routes.

mcp_kafka_proxy:
  type: mcp-kafka
  kind: proxy
  routes:
    - exit: kafka_orders_client
      when:
        - tool: produce_message
          topics: [ orders ]
        - tool: consume_messages
          topics: [ orders ]
    - exit: kafka_shipments_client
      when:
        - tool: produce_message
          topics: [ shipments ]
        - tool: consume_messages
          topics: [ shipments ]
    - exit: kafka_admin_client
      guarded:
        my_guard:
          - kafka:admin
      when:
        - tool: create_topics
        - tool: delete_topics
        - tool: alter_topic_configs
        - tool: alter_broker_configs

Configuration (* required)

exit

string

Default exit binding when no conditional routes are viable.

exit: echo_server

routes*

array of object

Conditional mcp-kafka proxy routes, matching by tool name and, for produce_message and consume_messages, by topic, then dispatching the matched tools/call unmodified to the route's own exit, or the binding's top-level exit when the route has none. At least one route is required. Routes are evaluated in order; the first matching route wins.

routes:
  - exit: kafka_orders_client
    when:
      - tool: produce_message
        topics: [ orders ]
      - tool: consume_messages
        topics: [ orders ]

routes[].exit

string

Exit binding — typically an mcp-kafka client connected to the target Kafka cluster — that a matched tools/call is forwarded to, letting different routes forward to different clusters. Falls back to the binding's top-level exit when omitted.

routes[].when

array of object

List of conditions (any match) restricting this route to particular tools.

routes:
  - when:
      - tool: create_topics
      - tool: delete_topics

when[].tool

string, array of string

Tool name matched by tools/call. Omit to match every tool not already claimed by an earlier route.

when[].resource

string

Resource URI matched by resources/read.

when[].topics

array of string

Topic name allow-list (exact names or * glob patterns) restricting this route to matching topics. Only enforced for produce_message and consume_messages, the only two tools that name a single topic as a routing key — every other tool either takes no topic or names one as a tools/call argument rather than a route match, so this list has no effect on them.

routes[].with

object

Reserved for a future per-route override. Currently has no effect: a matched tools/call is always forwarded unmodified.

routes[].guarded

object as map of named array of string

Roles required by the named guard for a tools/call against this route. Roles for the same guard are unioned into one entry; roles naming a different guard add a separate entry that must also authorize.

routes:
  - guarded:
      my_guard:
        - kafka:admin
    exit: kafka_admin_client
    when:
      - tool: alter_broker_configs

telemetry

object

Defines the desired telemetry for the binding.

telemetry.metrics

array

Telemetry metrics to track

telemetry:
  metrics:
    - stream.*

telemetry.attributes

object as map of named string properties

Telemetry attributes to add to the binding metrics.